The present invention relates to a carbonaceous aircraft brake disk comprised of a integral, strong, long life center core to which is bonded lightweight long wearing materials on each side.
Due to the complicated nature of fabricating an efficient and homogeneous carbonaceous aircraft brake disk that will function satisfactorily under all braking conditions, heretofore problems in cost and performance have been encountered. This is particularly true with respect to cost when new disks are required to replace the old worn disks and with respect to the production of a low wear disk brake which has suitable strength and a coefficient of friction.
Another problem encountered was that whenever disk brakes were refurbished with new wear plates as in U.S. Pat. No. 3,712,427, to Cook et al, the mechanical engagement effected by rivets would result in pealing, chipping, and cracking in the vicinity of the rivets. This largely was caused about by expansion of the wear plates during a braking operation which caused them to be heated to very high temperatures such as 2000.degree.C and above whereas the inter or core layer due to the often actual existence of an air interface would only be heated to a few hundred degrees centigrade. Additional factors were the actual movement of the rivet within its hole, thereby causing enlargement of the hole and unequal expansion between the rivet and the core layer as well as the side low wear layers. Moreover, refurbishment was largely limited to field operations and thus was costly.
Heretofore in the field of integral brake disks the disks have been made of the same material throughout. However, the amount of time to laminate the various layers was great due to the various coating and baking operation involved and it was not uncommon when such operations were carried out on a daily basis to involve a period of time of from 7 to 9 weeks. Hence, considerable cost is involved in the manufacture of such brake disks.